1. Field of the Invention
The present invention relates to an image display device and a program.
2. Description of the Related Art
An image display device in which two images are superimposed on each other using a half mirror is proposed (see, for example, Japanese Unexamined Patent Application Publication (JP-A) No. 8-122695). FIG. 4 of JP-A No. 8-122695 illustrates an image device with which a viewer may view a synthesized image obtained by superimposing a background image behind a half mirror and passing through the half mirror and an image reflected on the half mirror on each other.
The half mirror used in the image device of JP-A No. 8-122695 is produced by depositing a metal reflective layer such as a chromium or SUS layer as thin as possible, almost translucent, at least on one side of a glass material. Therefore, the half mirror is relatively expensive.
The half mirror described in JP-A No. 8-122695 has reflectance of 50% and transmittance of 50%. Although these numerical values are examples, transmittance of the background image is typically low in the half mirror because of the existence of the metal reflective layer.